You can set up a combination of soft synth/program combinations..As an example Hyper Canvas with a host program[Forte]..Winamp for Mp3's and waves..VanBasco for sequences...and Jammer live for arranger...All can interact and be displayed[accessed] on the computer screen..

There are other programs that combine sequences , MP3's and wavs in one program[KaraWin and Karafun]..Arrangers include OneMan Band..